This invention relates to storage bins for storing a flowable material, which may include, for example, an agricultural commodity such as grain; or other free-flowing materials such as fertilizers or cement. More particularly, this invention relates to a storage bin for storing grain in a water-impermeable environment wherein the grain bin includes a liquid impervious, perferably cone-shaped integral liner supported substantially entirely by a cavity in the ground adjacent to and beneath the liner. Still more particularly, this invention relates to a method for constructing a grain storage bin of the type described.
Grain crops, such as wheat, corn, oats and the like, have been cultivated for millenniums. The grain, in addition to its value as a foodstuff and its ease of cultivation, can be stored, under proper conditions, for long periods of time without deterioration. For proper storage, however, the grain must be placed in a storage facility which is designed to protect the grain from moisture and insects. It is especially important that the storage facility maintain the grain at a preferred moisture level, such as 10-12%, since insect activity, mold growth, and rot become significant problems at moisture levels above the preferred range. In addition, excess moisture can induce undesirable exothermic reactions in the stored grain.
The problem of grain storage has been highlighted recently because advances in grain growing techniques and equipment have produced grain harvests which have greatly exceeded existing storage capacity. Consequently, a need has arisen to increase storage capability with a minimum increase in cost.
In the past, two types of storage facilities, the steel hopper bin and the flat concrete floor bin, have mainly been used for the storage of grain. While both types of bin structures are adequate for the storage and handling of grain, they both have a number of disadvantages inherent in their respective designs.
The steel hopper bin is generally positioned above the ground surface and supported by a truss and brace system of steel beams designed to carry the weight of the bin and the stored grain. The bin, which may include a conical bottom, can be designed such that the grain can flow to a central portion for convenient removal by, for example, an unloading auger. While steel hopper bins function efficiently in the storage and unloading of grain, they are relatively expensive because of the amount of support steel required and the cost of labor needed to erect the bin. As a consequence of this cost disadvantage, steel hopper bins are beyond the financial ability of many grain farmers.
The flat floor bin structure is generally supported on the ground and, as the name implies, has a flat concrete floor upon which the grain is stored. The flat floor bin enjoys a significant advantage over the steel hopper bin in that the cost of material and construction is considerably less. However, the flat floor requires that the grain be removed from the bin by either manual labor or by mechanized means, both of which have disadvantages. Manual removal of the grain, for example, by shoveling, involves the cost of labor; the uncertainty of obtaining workmen when needed for an unpleasant, dirty job; and the exposure of the workmen to a dusty, dirty and/or moldy bin environment. Exposure to the dust and/or mold in a grain bin can cause an increase in sensitivity to the dust with repeated exposure and serious illness. Mechanized removal of the grain requires an investment in a bin sweeping apparatus and the labor cost of an operator. Mechanized bin sweeps pose a substantial injury risk to the sweep operator with the attendant rise in insurance costs and the risk of liability for injuries. As in the case of the manual removal of the grain, the bin sweep operator is exposed to the same health hazards posed by the inhalation of grain dust and/or mold.
In addition to the problems associated with the removal of the grain from the flat floor bin, the concrete floor, as with most concrete structures, is subject to minute cracking which can allow moisture into the grain. This moisture, as indicated above, can cause grain deterioration, an increase in insect activity, and undesirable exothermic reactions.
Consequently, it is an overall object of the present invention to provide a grain bin structure and method therefor which will store grain under desirable storage conditions and which overcomes the disadvantages of the prior grain storage structures.
It is an object of this invention to provide a liquid-impervious grain storage bin which is largely supported by the ground beneath and adjacent to the bin.
It is an additional object of this invention to provide a grain storage bin which utilizes a liquid-impervious preferably conically-shaped integral liner supported substantially entirely by a cavity in the ground adjacent to and beneath the liner.
It is a further object of this invention to construct a storage bin construction wherein an above ground portion of the storage bin is supported by a foundation which includes a footing supported by the ground and the below ground portion of the storage bin is also supported by the footing as well as by an identically-shaped cavity formed within the ground.
These and other objects of the invention will become apparent in a review of the following written description of the invention taken in conjunction with the accompanying drawings.